geller@eli.UUCP (David Geller) (05/10/87)
Here's the message I get when I run chkdsk on an AT compatible with a WDC controller and a Seagate 225 20Mbyte HD: Probable non-DOS disk. Continue (Y/N)? Typing either Y or N doesn't seem to do anything. The chkdsk completes and everything on the system seems quite normal. Any clues? Thanks David Geller UUCP: ..!seismo!sundc!eli!geller Electric Logic, Inc. Telex: 6503003778 2025 Eye Street, N.W., Suite 220 MCI Mail: PRESS Washington, D.C. 20006 Compuserve: 72667,1312
wtm@neoucom.UUCP (05/12/87)
In article <226@eli.UUCP>, geller@eli.UUCP (David Geller) writes: > Here's the message I get when I run chkdsk on an AT > compatible with a WDC controller and a Seagate 225 > 20Mbyte HD: > > Probable non-DOS disk. > Continue (Y/N)? > > Typing either Y or N doesn't seem to do anything. The > chkdsk completes and everything on the system seems > quite normal. Any clues? I've seen this happen when you have a BUFFERS=nn line in your CONFIG.SYS file. Sometimes, an errant application program will trash the copy of the FAT that is in the RAM buffer, thus causing the message, eventhough there is nothing wrong with your disk. Usually, rebooting the system is enough to make the message go away. If you still get a nasty message after rebooting, try booting up from a floppy with no CONFIG.SYS file. See if you still get the message. If all else fails, the boot block of your disk could contain an error or errors. The drive's partition table begins at offset 1BE (DOS 3.1) in the boot record (physical sector 0). The byte at 1BE is the boot indicator for partition 0. Byte 1CE is the boot indicator for patition 1. 1DE for partition 2. 1EE for partition 3. A drive can have only one bootable partition. For the bootable partition, the byte should be 80H. For all other partitions, the byte should be 00. 1C2,1D2,1E2,... are the operating system ID bytes for the respective partitions. For this, 00=unknown type, 01=DOS, 12 bit FAT, 04=DOS, 16 bit FAT. See page 9-6 to 9-8 of the IBM DOS 3.1 technical reference manual for further details. You might consider taking a peek at the boot record with DEBUG or the Norton Utilities if the message persists. Hope this is of some use... --Bill Bill Mayhew Division of Basic Medical Sciences Northeastern Ohio Universities' College of Medicine Rootstown, OH 44272 USA phone: 216-325-2511 (wtm@neoucom.UUCP ...!cbatt!neoucom!wtm)
waldman2@husc8.HARVARD.EDU (Bruce Waldman) (02/25/90)
CHKDSK on my D: drive (40 meg Miniscribe partitioned into C:,
D:, E:) says probable non-DOS disk. Continue? Norton and Mace
find no problems with FAT tables or in any files. No mixing
of DOS versions on the disk. I boot up from C:, so no problem.
Should I be worried?
Bruce Waldman, waldman2@husc4.harvard.edu
!harvard!husc4!waldman2
bw@harvarda.bitnetdlg6627@uxa.cso.uiuc.edu (02/26/90)
I have exactly the same problem using Seagate 40 Mb (ST251-1). Seems to me that it is not because of brand name of HD. It may be due to MS-DOS itself ????
elund@pro-graphics.cts.com (Eric Lund) (02/26/90)
> CHKDSK on my D: drive (40 meg Miniscribe partitioned into C:, > D:, E:) says probable non-DOS disk. Continue? Norton and Mace > find no problems with FAT tables or in any files. No mixing > of DOS versions on the disk. I boot up from C:, so no problem. > Should I be worried? > Run the MACE program NONDOS. Something has fiddled with your FAT, and changed the drive descriptor attribute. This tells the world if the drive is a DOS disk or not. It should be set to F8. NONDOS will fix the byte. You should be somewhat worried, because something wrote data where it shouldn't have, and you should locate the culprit. Eric W. Lund *DISCLAIMER "Disclaimers are for weak people."* Prodigy: xcbr22b UUCP: ...crash!pro-graphics!elund *COWS FOR RENT* ProLine: elund@pro-graphics Internet: elund@pro-graphics.cts.com ** ARPA/DDN: pro-graphics!elund@nosc.mil
elund@pro-graphics.cts.com (Eric Lund) (02/28/90)
> I have exactly the same problem using Seagate 40 Mb (ST251-1). > Seems to me that it is not because of brand name of HD. It may be > due to MS-DOS itself ???? No, see my other message. Something fiddled with your File Allocation Table. If you have MACE Utilities, run NONDOS to fix it. If not, get the PAUL MACE GUIDE TO DATA RECOVERY. If both options are out, do you have PCTOOLS or NORTON UTILITIES? If so, drop me a line and I'll detail the necessary cure. Eric W. Lund *DISCLAIMER "Disclaimers are for weak people."* Prodigy: xcbr22b UUCP: ...crash!pro-graphics!elund *COWS FOR RENT* ProLine: elund@pro-graphics Internet: elund@pro-graphics.cts.com ** ARPA/DDN: pro-graphics!elund@nosc.mil